1. Field of the Invention
The present invention relates to a gasket and a high-pressure pump comprising said gasket. The invention particularly relates to a gasket and to a high-pressure fuel supply pump for an internal-combustion engine.
2. Description of the Prior Art
High-pressure pumps generally comprise a pump body, at least one pumping element defined by a cylinder and piston, and a cylinder head. The pumping element receives fuel from a low-pressure supply line, compresses it and sends it, along a high-pressure delivery line, to a high-pressure manifold or “common rail” as it is commonly known.
To prevent fuel leaks it is normal to use an essentially flat gasket placed between the pump body and the cylinder head: this gasket has a first hole defining part of the low-pressure supply line, a second hole into which the cylinder head can be inserted, and a third hole defining part of the high-pressure delivery line.
Document DE 103 10 124 discloses a flat gasket with a sealing edge that extends around the first and third holes, creating a sort of embankment against potential fuel leaks from the first, second and third holes.
However, this type of gasket has proved to have a number of disadvantages. In particular, even when subjected to leak tests before being sold, gaskets of this type are often returned by the buyer as they do not give early indications of fuel leaks, which develop over the long term.